# name : SAS do by until ()... end, for set
# key : loop.do.by.until.for.set
# contributor: Shuguang Sun
# --
do _n_ = 1 by 1 until (${1:last.id});
set ${2:din};
by id;
sum = sum(sum, var);
$0
end;

mean = sum / _n_;
